Gases

A variety of gases are used in semiconductor manufacturing for process reactions in chemical vapor deposition, etching, ion implantation and many other processes. They are also used for such diverse purposes as chamber cleaning and purging. Generally speaking, gases are classified as processes gases for the first set of applications and bulk gases for the second. Bulk gases are hydrogen, helium and nitrogen, for example, which can be produced on-site through air separation plants. Process gases are typically supplied in the familiar gas tanks, or sometimes gas tanker trailers if the volume required is high enough. In some parts of the world, underground piping is used to supply multiple fabs

Aside for the gas type, the most common concern is the purity of the gas. Purity is often discussed in the “number of nines” level of purity. Gases that are 99.999% pure, for example, are “five nines” purity, gases that are 99.9999% pure are “six nines” purity and so on. Alternatively, trance contaminants are measured in parts per million (ppm), parts per billion (ppb) or even parts per trillion (ppt). Higher levels of purity are, of course, more difficult to produce and are therefore more costly. They are also more difficult to measure accurately. An ongoing challenge in the semiconductor industry is that gas users — IC manufacturers — tend to specify the highest level of purity available, but it’s often unknown if that higher level of purity actually provides any kind of benefit to device performance or yield. Indeed, sometimes trace impurities have proved to have some kind of beneficial effect and removing them can actually decrease performance.

Another important aspect — some would say the most important aspect — is safety. Gases can be toxic, carcinogenic, flammable, pyrophoric, corrosive and generally hazardous. A silane leak, for example, could result in a pocket of silane in a corner of the fab, which could explode. Arsine and phosphine, commonly used in ion implantation, are deadly in ppb and ppt, respectively. Fortunately, the semiconductor industry has an excellent safety record and danger to fab personnel is minimal — as long as established safety protocols are closely followed. This include storing gas cylinders in well monitored gas cabinets.

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Keysight Technologies' popular 276-page Parametric Measurement Handbook is an invaluable reference tool for anyone performing device or process characterization. It is filled with tips to help both novice and advanced users, and the latest edition (Rev 4) includes an entirely new section devoted to power device test.September 13, 2018Sponsored by Keysight Technologies

For many, formal reliability verification is a new process. Foundry-qualified and foundry-maintained reliability rule decks enable design and IP companies alike to establish baseline robustness and reliability criteria without committing extensive time and resources to the creation and support of proprietary verification solutions. In addition, as reliability verification needs expand, customer demand drives the development and qualification of new and augmented reliability rules.August 30, 2018Sponsored by Mentor Graphics

WEBCASTS

In semiconductor manufacturing, traditional root cause analysis using FDC summary data is not always effective in solving complex issues, especially when the defect signals are too subtle to detect. Full trace analytics enables the discovery of these hidden signals. This allows fab engineers to accurately pinpoint the root causes of yield-impacting issues. This webcast will discuss several use cases to showcase how advanced full trace analytics can help not only in provide accurate results, but can also simplify the root cause analysis process and reducing time-to-root-cause, resulting in better yields, lower production costs and increased engineering productivity.
In this LIVE webcast, BISTel's Chief Product Management Officer, Gabe Villareal will discuss how BISTel is leading the industry with its new full trace analytics to simply root cause analysis, which enables fab engineers to pinpoint the issues than impact yield and productivity quicker than ever. Full trace analytics enables the comprehensive examination of process trace data to allow the detection of abnormalities and deviations to the finest details.

The semiconductor industry is an acknowledged global leader in promoting environmental sustainability in the design, manufacture, and use of its products, as well as the health and safety of its operations and impacts on workers in semiconductor facilities (fabs). We will examine trends and concerns related to emissions, chemical use, energy consumption and worker safety and health.

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